Toxicological effect of freshwater algae co-exposure to Cd and 4-n-nonylphenol (4-n-NP) was seldom reported. In the present study, Chlorella sorokiniana was selected for testing the single and combined effect of Cd and 4-n-NP by detecting the growth inhibition and oxidative stress after exposure for 48 h, 72 h, and 96 h. The combined effects were evaluated by using toxic units (TU) method and concentration addition（CA）model. The synergistic effect of mixture on algal growth inhibition was both observed at 48 h and 72 h, and the additive effect was observed at 96 h. In addition, the significant alterations of superoxide, thiobarbituric acid reactive substances and antioxidant defenses (superoxide dismutase, catalase, glutathione) have been detected. It could be observed that the mixture predominantly lead to synergistic effects in superoxide induction, and the antagonistic effects in the GSH induction. A similar trend between the superoxide induction and growth inhibition were observed, which may indicate that the oxidative effects of Chlorella sorokiniana contributed to the growth inhibition after exposure to Cd and 4-n-NP. These findings may have important implications in the risk assessments of heavy metals and endocrine disruptors in the aquatic environment.

很少报道淡水藻类与Cd和4-n-壬基苯酚（4-n-NP）共同暴露的毒理作用。在本研究中，小球藻通过检测暴露48 h，72 h和96 h后的生长抑制作用和氧化应激，选择Cd和Cd和4-n-NP的单一和联合作用。采用毒性单位（TU）法和浓度加成（CA）模型评价其综合作用。分别在48 h和72 h观察到混合物对藻类生长抑制的协同作用，在96 h观察到累加作用。此外，还发现了超氧化物，硫代巴比妥酸反应性物质和抗氧化剂防御（超氧化物歧化酶，过氧化氢酶，谷胱甘肽）的显着变化。可以观察到，混合物主要在超氧化物诱导中产生协同作用，而在GSH诱导中产生拮抗作用。观察到超氧化物诱导和生长抑制之间的相似趋势，Sorokiniana小球藻暴露于Cd和4-n-NP后有助于生长抑制。这些发现可能对水生环境中重金属和内分泌干扰物的风险评估具有重要意义。